Paper pulp screening machine



Feb.5, 1935. t. l v N'. M. KNIGHT v 1,990,283

` PAPER PULP SGRE'NING MACHINE Filed sept. 17, 1932 2 sheets-sheet 1Nelson lVLKnghT Feb. 5, 1935. N M. KNIGHT PAPERPULP SCREENING MACHINE 2Sheets-Sheet 2 Filed Sept. 17, 1932 4 ATys.

lnvenTor. Nelson lVLKnghT MSM-kw Patented FeJrS, 1935 i T712' l I a'UNHEDSTATES PATENT'OFFICE-g1* v v 1,990,2ss "PAPER PULP SCREENINGMACHINE Nelsonk M. Knight, Brookline, yMass. v Application september17,1932, serial Na'eaasec.

* 11 claims. (c1. 'az-34)'v i i This invention relates to a machine forscreenis formed, circular end frames'l secured to the ing paper pulpvandparticularly to that type of base 6, and end walls or lend members whichpaper pulp-screening machine which comprises` ormfthe ends of the vat orcasing and are a vat or container having van inlet and an outsuitablysecured to the endframes 7. Thedis- 'let, a cylindrical screen situated`within the vat charge-ports 3 are formed in these end members A 5between the inlet' and outlet, a plunger or pulsa.- 8 and the dischargeconduits 141 are secured' to tor within the screen, and means to vibratethe 'saidv end members: The end members -8 are samein the directionofthe axis of the screen, vformed with conical-shape inner'faces asindi'- such operation keeping the pulp agitated and also cated at 9, theapices of the :conical 4faces 9 l0 assisting-to keep the screenclear. yl being directed toward each other. :L 1'0 Oneobject of my presentinvention is to pro- The enclosing side Walls 10 of the'vatvor casvidean improved pulp-screening machine of this ing `1 are in the form ofside plates`50 which are type which has novel means for keepingtheysecured at their lower edges to the basememscreen plate clean. ber 6and at their upper edges -toatop frame Another object of ther inventionis to provide ymember 111 which extends from-onefend-frame`1`5 apulp-screening machine which will have an in- 7 to the 4other` and issecured to bothrend'frames. .v creasedpulp screening capacity and at thesame This'topl frame member 11 is provided with an ytime a relatively10W power consumption for op- "opening 12 through which the dirtscreened from eration. y 'the-pulp may be ejected. lThe side plates 50 i50* Another 'object ofthe invention vis to provide a are also securedatftheirends to the endframes'7. 20 vf pulp-screening machine which hasrelatively few The cylindrical screenmember is "stationarily movingpartsand which is constructed to ensure supported onV the end members .8.`For this ypurlong'life; posev said end members are formed'with annularOther objectsy of the invention are to improve seats 13 whichareencircled by the ends of the '25j generally Vpulp-screening machinesinthe par- `screen 5, the latter-being clamped to said seats 25tcularshereinafter'set forth. bymeans of two-part clamping vrings 14which the drawings wherein-I have illustrated a encircle the ends ofvsaidscreen and the meet- @selected embodiment of my invention,y Fig. 1ing ends of which are clamped together asindijis' avertical sectionalview through a pulp-screencated at 1 5.

"l30'ingmachine embodying the invention taken. on Situated within the'stationary cylindrical I 30 "a5-lar section line 3-3, Fig. '1. A l

theline 1 1, Fig. 3; y l screenv is la plunger or pulsating member indi-Fig. 2 is an end viewof the pulp-screening cated generally at 16 l"andwhich is shownv as machine looking from theright Fig.-1; v mounted upona shaft 17-that slides back and Fig. 3 is a section onsub'stantially theirreguforth in bearings 18 formedl inl the end mem-.

l ybers 8. The plunger v16 is in the shape 'vof fa `The machine hereinshown comprisesA a cas- -doublecone,that is, the opposite faces19fthereof 7ving' vor housing indicated generally at 1 and arecone-shapedgwith the. apices of the conesy which is provided -in .itsbottom with an inlet directed in opposite directions'.y This pulsatingport 2 throughwhich the pulp to bescreened is member 16 has adiametricaldimen'sion suflicie'nt 4"F40 delivered to the vat, vand with"an outlet port 3 to nearly fill theA cylindrical `screen A5. Means 40'at each end through which the screened pulp are provided for vibratingVthe shaft 17 "and the is discharged from the 'vat or casing 1. EachIplunger 16 in an axial directions Such pulsatinlet port 3 communicateswith a delivery coning-movement operates to` forcethe pulp back rduit 4through which the Vscreened pulp-is'deand forth through thescreen-:thereby to keep 545 liverd. 'l the latter from'cloggingup. v f45 Situated within the vat or casing -1` and be-l LWhile any suitablemeans may befemployed tween theinlet 2 and'discharge ports 3 isacylinforthuspulsating ory vibrating ythe plunger 16 drical screenjmember so thatin passing from Ihave herein illustrated for this purpose a drive ``theinlet to4 the discharge ports the pulp is; shaft 20`which is vjournalledin a crankcase "m0 'compelled topass through't'he screen member, housing21; Said housing isfshown as secured 50 thisbeing a common constructionin pulp-screento a draining drum 22 whichin `turn is secured ingmachinesof this type. to one of the heads 8 A v yWhilethe vat or casmg 1may have anyfsuit- The shaftl 20 which may be driven by a pulley yableconstruction that herein shown comprises' 23 or by'any suitable means,is'provided with y 55 abase member in which Vthe inlet opening 2aneccentric 24 whichis'encircled'by'an'eccentric 55 y 'fthe right handdischarge port 3 into the dis- Ycharge conduit 4 while another portionof said d 1 s l 8 may be drainedaway, vand -will thusbezpre-ego f1.0wi11cause Vthe vhm-water4 mixture tenues strap 25 carried on the end of alink or connectin'g rod 26. This connecting rod is pivoted at 27 to oneend of the shaft 17 which projects through the draining drum 22 and intothe crank case housing 23. Said housing maybe'supplied with oil asindicatedy at 28 to provide lubricathrough which the dirt, foreignmatter and other,

materialto, be ejected, is discharged and the pu1p win be delivered totheeinletz, which 'itY will be noted is. situated centrallyfat thebottomof the Vat or casing under a sufticient'sheadutc maintain the tankfilledffatrlcastuptoand preferably slightly into the opening inIthefframe lmember 11.

e When the plungerglmoves tothe rightFig.' 1

the chamber .V39 .between the ,right hand Vface 19 of the plunger 16andthe right hand head memberk 8 .will be reduced in size with, theresult that, aportion of the paper pulp oriibre-water.

v-mixture Whichvis within the screenand which, therefore, has beenscreenedfis forced vthrough screened pulp will be forced outwardlythrough the screen 5 During this same stroke of the ,plunger 16 by whichthe chamber 39 is decreased ,v

, in sizevthercharnber 40 on the opposite sidev of the plunger willbeincreased insize and the lincrease will.. produce a reduction. .inpressure i withinthe chamber ,4;0.vv yThe forcingof the pulp outwardlythrough the screen fromthe chamber 39 as above kdescribed tends tocreate an increased pressure of the pulp ontheoutside of the screen.

esetherx-Wthrthe'redueed; pressure in the chamber v,iulufurdly throughthe Screenvinto the y ehanber 40. Hencevwh'en the plungerlfmoves to the,Y

right there will be a flow -ofliibre-water mixture outwardly-through the`screen y from the; chamber -31 endtethe right between the screenandtheeasing and 'inwardly through the eereeniinto the chamber`40. f A 's Whenthe kplunge'relt'` is -mvedin theppposite -direction or to the left,inrv Fig,Y 1 thechamber 40 .will 'be decreased :size and the ,chamber39T wulbe increasedinfsize- 'me'reductionin l size of thechamber 40,will cause.; part .o1-'the fibre-Water mixture. therein@ be. forcedLout- 4vyardlythrough the rleft hand discharge port 3 and will also causepart of 'saidiibre-water mix ture to be Vforced'.outwardly through` the.screen` y f'lint'o `the space between the screen and thebwalls of thecasing, :therebyftending tdincrease the pressure ofthe fibre-Watermixtureoutside kof "31Vtends`to reduce the pressure of, said,r chamberand this together with the pressure of the flbre- "water mixture outsideof the chamber causes a lThis pulsating of the. spreeWeter`V mixture''through the screen servesk 'to preventltlieA screen l from 4becomingclogged 'and fduringfthis loperation the dirt orforeig'n matter. whichAisfscreened 1 from the pulpor'fibre-water mixtureiwill remain on theoutside of the screen'and VV.willi be "dis-w v charged throughthefopenng1,2 of the tcpfframe fable fwater, Seals 33W Prevent leakage -0f 'Water`alongthe shaft..'4'I'he drainingA Adrum 22 V-h;as an This increasedpressure outside` vthescreen toy vibrati1 1g therewith.

11 into a suitable receptacle as usuall in pulpscreening machines ofthis general type.

To assist in keeping the screen clean I have' provided a plurality ofcleaner rings 29 which are -situated within the rcylindrical screen 5and are of a size` so that their peripheries are closely adjacent theinner face of said screen. These cleaner rings are connected to theplunger 16 and thus `have pulsating or vibrating movements therewith.These cleaner .ringsare #shown as annular rings. which are. "mounted IonIfrods 30 that are supported in the peripheral' portion of fthe plunger16. The adjacent rings are separated kby suitable spacersv 31 carried bythe rods. The

peripheries oft-he cleaner rings 29 are preferably 15 `beyelled as shownat 32 and the bevel faces 32 of the cleaner -rings on the right handside of -theplunger' are bevelled in an opposite direc.- tion from thoseon the left hand side of said plunger. The vibrating movement of these2o e1eanerrinss assiste the; action 0f the plunger in keeping .thescreenifrom clogging y.up during the screeningioperation. .Y I s' sA'Ihe head Lmembers `8 ,are provided Withsuit- `AOpening `34u11vits:betihnfl and it provde-ins whereby any waterfwhich Vmayleak v.pastthe watergseal in the, right hand vhead {member vented from beingcarried into .'thefcranlgcasing-21.., lr lIclaim:`

1. Apulp-screeningmachinehcomprisingalcasy 1;, ing `havinggan inletandanputletfa cylindrical e.2.@A.pulp-screeuinamaehine@Qmiiesesinghaving an inlet and an outlet, a cylindrical screen within saidcasingsituated -betweenthe inlet and.the1out1et,a plunger v element'within.the545 cylindrical screen,A means .to vibratesaid element anaxiale-direction, end .a Series vOfiffwfitn- 1 cleaning rings extendingfromv fone 4end of yfthe screen tothe other?, means for securing saidngs.;,.t0 the v4plumzer te 'vibrate -therewith, saidlrinssiuo having theirperipheri'es k.closely adjacent 'A1/.the

A, inner facej of the screen. i

3. A pulpfscreeuinamachinecemprisinaeasv,ing havinganinletfand an.outleaa cylindrical screen within said casing, situated between Vftheliizuetandthe Qutlet eiplunserfelemeutthe y cylindricalscreen, means tovibratesaid Aelement 1in an i axial .directicm rods carriedby saidplunger .andextending -paral1elto-the-axis of ythe cylin. derandpcleaner rings mounted in-s'paced ire1ation0 n s Y Y y on saidrods,the peripheriesoffthe.cleanenrings `:the-screen. The increase in sizeofy the chamber n being situated Iclcsely adjacent the inner l face lof4. A1 pulp-Screening mach-ine Comrrifng 65S- ing having an inlet and anoutlet, a cylindricalfl screen within'said casingsituated betweenrtherinlet and the outlet,`jap1unger:element-:Within-Jihe and projectingfromfeach `facetlierec.andcleanifl yerrringscarl'xjied by the rods eachSideff'the plunger. ,y 5. t.A pulp-screening" achine ving having acentralinlet and an outletateach neI1y;1,eacli end wall of the shaped, acylindrical screen within the casing situated between the inlet and theoutlet, a shaft mounted in bearings in said end walls, a plunger carriedby said shaft and having cone-shaped ends, means to reciprocate theshaft in the direction of its length, and cleaner rings secured to andreciprocating with said plunger, the peripheries of the cleaning ringsbeing situated closely adjacent the inner face of the screen.

6. A pulp-screening machine lcomprising a casing having a central inletin its bottom and a discharge port in each end, a cylindrical screenstationarily mounted within the casing and situated between the inletand lthe discharge ports, a plunger element Within the cylindricalscreen, and means to vibrate said plunger element in an axial direction.

7. A pulp-screening machine comprising 'a casing having an inlet and anoutlet, a stationary cylindrical screen within the casing situatedbetween the inlet and the outlet, a plunger element within thecylindrical screen,.means to vibrate said element in an axial direction,and a series of .screen cleaning rings extending from one end of thescreen to the other and carried by and moving with said plunger.

8. A pulp-screening machine comprising a casing having a cylindricalsidewall and two end members to which the side wall is secured, saidside wall having a central inlet in the bottom of the casing and eachend member having a discharge port therethrough, a stationarycylindrical screen situated between the inlet and the discharge portsand having its ends supported by and stationarily mounted on the endmembers, a plunger element within the cylindrical screen, and means tovibrate said plunger element in an axial direction.

' 9. A pulp-screening machine comprising a cas,- ing having acylindrical side wall and two end members to which the yside wall issecured, said side wall having a central inlet in the bottom of thecasing and each end member having a discharge port therethrough, acylindrical screen situated between the inlet and the discharge portsand having its ends supported by and mounted on the end members, aplunger element within the cylindrical screen, means to vibrate saidplunger element in an axial direction, and means separate from theplunger but mounted thereon and vi.- brating therewith for cleaning thescreen throughout its entire length.

10. A pulp-screening machine comprising a casingfhaving a side Wall andtwo end members, said side wall having an inlet in the bottom of thecasing and each end member having a discharge port therethrough, astationary screen situatedbetween the inlet and the discharge ports,

said screen having a tubular shape and having its ends secured to andsupportedby the end members, and means within the screen to cause thepulp to flow back and forth through the screen during its movement fromthe inlet to the dischargey ports.

l1. A pulp-screening machine comprising a casing having a sidewall andtwo end'members,v

said side Wall having an inlet in the bottom of the

